There is an antifreeze smell coming from my pickup but I cannot see any leaks. What could be causing it?

Question

I have a 2000 GMC Sierra and I have been smelling antifreeze when I have the windows down, with window up I do not smell the antifreeze, don't believe it is the heater core, no leaks visible. Any ideas?

Answer 1

If your heater core was leaking, you would smell antifreeze with the windows rolled up, because air passes through the heater core as it's pumped into the cab. That's how the air becomes heated.

If you smell antifreeze with the window down, the airfreeze is coming from outside the cab.

I experienc ethe same thing, but have never found evidence of a leak. I think the smell comes from the coolant overflow tank. As the engine heats up, the coolant expands and is forced into the overflow tank. When coolant enters the tank, if forces air in the tank out through the vent hole. I believe this is the source of the antifreeze smell.

Just keep an eye on the coolant level in the overflow tank and the radiator. (But don't open the rediator cap is the engine is hot!)

Answer 2

Check the thermostat, also there might be a leak but only when the car is running, so you might not see it

Answer 3

You don't always see leaks. Check under the water pump. there is a small hole. Called a weep hole. some times leak only when running. turn off engine and feel under there if wet replace the water pump.. I say water pump because you can't smell it with the window rolled up. Good luck

Answer 4

check under it at the water pump. it could be leaking there and blowing away far enough to not leave a puddle